IN THESE difficult times it is fortunate to have cause to celebrate some remarkable achievements of the human intellect. It cannot have escaped your notice that this week commemorates the 200th anniversary of Charles Darwin's birth. This comes hot on the heels of last year's 150th anniversary of the publication of his epochal work On the Origin of Species, which revolutionised the nature of biology and our understanding of both human origins and our relationship to other species on this planet.
This year also commemorates the 400th anniversary of Galileo's use of the telescope to unveil the properties of the heavens, including the discovery of the moons of Jupiter. This changed forever our picture of our place in the cosmos. In honour of this, UNESCO has declared this the International Year of Astronomy.
There are remarkable commonalities between the intellectual implications of both Darwin's and Galileo's achievements. Both provided new, vital and unexpected connections between humans and the rest of the physical world.
Darwin's theory of evolution, and the science of genetics which followed, demonstrate that humans and the rest of life on Earth share not just a common heritage, but virtually everything else. At a molecular level, the distinction between humans and bacteria seems almost superficial. All forms of life on Earth share a common genetic method of replication and energy storage. Yet it is truly remarkable that from so simple a set of molecular building blocks such diversity can arise.
Since the days of Galileo, astronomy has established a fundamental connection between humans and the cosmos. We have learned that "star stuff" and "earth stuff" have the same elemental composition. The very atoms in our bodies come from the stars. Almost every element on Earth originated in the fiery core of one of many, now long-dead, stars, whose cataclysmic ending in a supernova spewed materials out into the galaxy that eventually coalesced in our solar system 4.6 billion years ago, as the sun and Earth formed. We are literally star children; a fact I found so poetic that I devoted an entire book to exploring the cosmic life of a single atom.
Perhaps the greatest strength of science is to unveil otherwise hidden connections between seemingly disparate phenomena, changing our perspective on our place in the universe. Accordingly, the two discoveries we herald this year carry an important message for our future: the intimate connections between humanity and the entire cosmos, as illustrated by both evolution and astronomy, suggest that the only sensible perspective of humanity is a global one. The need for a global perspective is of vital importance now, as we are the first generation in history that must seriously confront global limits to our future on Earth, from energy to climate change.
But I don't want to end on a pessimistic note. Science raises the human spirit. Surely a civilisation that produced these remarkable intellectual leaps can amass the wisdom to tackle the new challenges we face.
What Darwin and Galileo did most fundamentally was celebrate the true beauty of nature. Perhaps Darwin put it best, in a quote at the end of On the Origin of Species which applies equally well to the astronomical world as it does to the biological one: "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."
Lawrence Krauss is director of the Origins Initiative at Arizona State University in Phoenix